The engine will fail to start unless （）. ["the pressure of the starting air is high enough","there is enough air in the air reservoirs","the air is supplied into the cylinders in the appropriate sequence","all of the above"]
控制陆架沉积的因素有哪些？
大船准备回收救生艇时，应降低船速并将救生艇置于大船的（）。 ["上风舷","下风舷","随便"]
期权宝（个人外汇期权交易）的签约渠道为（） ["A.网银签约","B.柜面签约","C.电话签约","D.自助终端签约"]
私募股权基金主要的投资对象是（） ["上市公司股权","非上市公司股权","上市公司债券","非上市公司债券"]
简述血液循环障碍。
